Fig. 2
Example of determination of cranial contribution to cranio-spinal compliance from sample input and output waveforms. a Flow compensated magnitude image showing bright signal from blood vessels. b High-velocity encoding images used for measurements of arterial inflow and venous outflow. c Low-velocity encoding images used for measurements of CSF flow. d Phase contrast MRI derived cardiac cycle of QA−V (red) and QCSF (green) in an 21-year-old healthy female subject is plotted. QA−V is used as input to the model, which predicts the inverted QCSF (black) waveform. e Histogram corresponding to model-derived spinal contribution to cranio-spinal compliance, CS/(CC + CS), is plotted for all the model parameters that give E > 0.7. The final spinal contribution to CSC is chosen from the mode of the histogram (60%)